A technique of using cells isolated from tissue for tests and examinations is essential in biotechnology-related fields. Such a technique is widely used for a diagnosis of diseases and pathoses, a search for a new drug and an assessment of its effect, an animal inspection, a plant inspection, a test of an environment pollutant and so on. Therefore, cells used in the biotechnology field are becoming increasingly diversified.
Although some isolated cells are immediately used for tests in a floating state, others are cultured in a state of being adherent to a culture dish and used for various tests and examinations in most cases. Primary cells and cell lines used for cell culture are required to exhibit drug sensitivity, toxicity reaction or the like of a similar level to a test in vivo, so-called an in vivo test. In other words, an in vivo-like cell function is required in a cell culture container. Further, because isolation for obtaining primary cells is complicated and cell culture lines used for a cell culture test are expensive, a test method with a small number of cells is desired.
In the above-described cell culture test, its effect is measured under the same conditions while changing the amount, concentration, and the like of the drug or the like to be evaluated. Therefore, the cell culture containers need to be identical in material, shape, and the like. As for the cell culture container, a plastic petri dish, a glass petri dish, a glass plate fixed in a container, a well plate, and the like are usually used. Examples of the well plate include plates and petri dishes each including 6 wells, 12 wells, 48 wells, or 96 wells. In general, these plates have substantially the same overall size. Therefore, as the number of wells increases, the size of a single well becomes smaller. A single well corresponds to a single culture dish. With the recent trend toward miniaturization, a 384-well plate including a number of culture dishes with a small diameter has also come to be used. The bottom of each of these culture dishes has a flat plate shape, and this bottom surface is used as a culture surface.
However, when a conventional cell culture container is used to culture tissue cells, these cells sometimes lose their original functions, thus causing dedifferentiation. This causes a problem that the intended cell function is not developed.
To solve the above-described problem, an attempt to coat the surface of a culture container with biological material (such as glycoprotein and protein) derived from a human or an animal (see Patent document 1) as well as an attempt to culture such material in a polymer gel (see Patent document 2) have been made.
[Patent Document 1]
Japanese Unexamined Patent Application Publication No. 8-317786
[Patent Document 2]
International Patent Publication No. WO03/006635